A Preliminary Study on the Green Synthesis, Characterization, In Vitro Antioxidant, Anti-Inflammatory, And Cytotoxic Properties of Silver Nanoparticles Using Both Aqueous and Ethanol Leaf Extracts of Annona Muricata (Soursop)

The use of nanoparticles across various fields has garnered significant attention due to their unique properties and diverse applications. This preliminary study explored the green synthesis of silver nanoparticles (AgNPs) using aqueous and ethanol extracts of Annona muricata (soursop) leaves as reducing and stabilizing agents. The AgNPs synthesized using leaf extracts were characterized by FTIR, SEM-EDX, TEM, and DLS analyses. The FTIR spectra indicated the presence of phytochemicals acting primary as reducing and capping agents. SEM analysis revealed predominantly spherical to quasi-spherical nanoparticles with sizes ranging from ~20-70 nm, while EDX confirmed the elemental presence of silver (Ag). TEM showed mostly spherical nanoparticles with sizes ranging from ~3-30 nm (AgNPs synthesized from 5 mL ethanol extract) to ~10-40 nm (AgNPs synthesized from 3 mL aqueous extract). DLS analysis indicated moderate polydispersity and negative zeta potentials (-21.7 mV to -29.4 mV), suggesting good colloidal stability, with ethanol-derived AgNPs exhibiting superior properties. The AgNPs displayed significant, concentration-dependent in vitro bioactivities. Those synthesized with 5 mL ethanol leaf extract exhibited the highest ferric reducing antioxidant power (FRAP: 324 μg AAE/mL), DPPH radical scavenging (64.29%), and ABTS⁺ scavenging activity (73.9%). They also demonstrated potent anti-inflammatory activity (78.82% BSA denaturation inhibition at 50 μg/mL), surpassing the standard drug diclofenac sodium, along with notable cytotoxicity in the brine shrimp lethality assay (LC₅₀: 32.5 μg/mL). These findings highlight the effectiveness of A. muricata leaf extracts, especially ethanol extract, for the eco-friendly synthesis of AgNPs, yielding nanoparticles with promising antioxidant, anti-inflammatory, and cytotoxic potential.